Gas flow indicator



Jan. 11, 1944. s. v. wlNToN v 2,338,750

GAS FLQWfINDICATOR Fil'ed DeQ. 8, 1941 5 `{ll/11111114 vlllllll//l YPatented Jan. l1, 1944 UNE'E) STATES i? Tam OFFICE.

2 Claims. (Cl. 20G- 83) (Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

The present invention relates to means for providing each member of an aircraft crew receiving oxygen from a common source with a positive warning in the event that his individual flow of oxygen is interrupted.

Another object of the invention is to provide additional means whereby the commander of such an aircraft is simultaneously warned as to which one or more of his crew members is failing to receive an uninterrupted supply of oxygen from said common source.

This invention is equally applicable to the individual members of a submarine crew receiving oxygen from a common source or to their commanding oiiicer as a means for determining the location of oxygen supply interruption to any one or more of the aforesaid individual crew members.

Other applications of the invention will be apparent from the following descriptions of the presently indicated embodiments thereof taken in connection with the accompanying drawing, wherein:

Fig. l represents a sectional view through a purely schematic representation of the pressure sensitive or reacting portion o'f my invention;

Fig. 2 is a diagrammatic representation of the signal portion of my invention which pertains to the individual crew members;

Fig. 3 is a diagrammatic representation ofthe signal portion of my invention which pertains to the crew commander; and

Fig. i is a cross-sectional View through the pressure sensitive or reacting portion of one embodiment or invention.

rlhe combined parts illustrated in Fig. l are hereinafter referred to as constitutingv a pressure reactor l. rlhe pressure reactor I is made up of a conduit provided with a Venturi orioe 3 and a negative pressure escapement hole 4 located down iiow of the Venturi orifice 3; of i a metallic chamber 5, iixed to the conduit 2,

having its sealed end connected to the escapement hole fl by means of a connecting hole G and its open end provided with a threaded recess l; of a -flexible metallic diaphragm 8, seated at the bottom of the threaded recess "I, having a silver tipped contact point 9 centrally disposed upon the upper or exposed surface thereof; of a diaphragm clamping ring IB, constructed of any suitable insulating material, with an inwardly tional numeral 2,8.

projecting lug II having an axially located threaded hole I2 and locking screw I3; and of a threaded (metallic) conductor I4, having a silver tipped contact point againstl movement by means of two lock nuts I6. Phantom wire terminals I1 and I8 are shown, respectively, between the lock nuts I6 and beneath the locking screw I3'.

Operation of the pressure reactor I can be best understood following a brief description of the diagrammatic showing of Fig. 2. In the latter figure, a main or common source of oxygen supply IS is piped to members A, B and C. and to commander D of an aircraft (in which all personnel are equipped with oxygen masks) through two ante shut-off Valves 2B; a regulator control 2l, four post or individual shut-off valves 22; and the four individual pressure reactors I. As typically numeralled for crew member A, the wire terminal I1 is connected to one pole of a single throw switch 23; the remaining pole of the switch 23 is connected to one pole of a signal lamp 24; the remaining pole of the lamp 24 'is connected to one pole of a battery 25; and the remaining pole of the battery 25 is connected to the wire terminal I8, thus completing As signal circuit. For the purpose of future reference; Bs signal lamp is identified by an additional numeral 26, Cs lamp by additional numeral 2l, and Ds lamp by addi It is of course further assumed that the right hand portion of the conduit 2, of Fig. 1, is in direct connection with the post shut-off valve 22 and that the left hand portion of the aforesaid conduit 2 is directly connected with the oxygen mask worn by the crew member A.

Refering jointly to Figs. 1 and 2, the four post shut-off valves 22 are first carefully closed such that no pressure differential exists between the top and bottom surfaces of the flexible metal diaphragms 8, due to complete absence of oxygen ilow through the conduits 2. Following additional closure of the four single throw switches 23, the conductors I4 of crew members A, B, C, and of commander D are each individually screwed down until the silver tipped contact points 9 and I5 are brought into just that degree of engagement which will assure continuing operation of the signal lamps 24, Z, 2l and 2B under zero flow conditions. Following accomplishment of the above described Contact point adjustment, the four conductors I4 are fixed against future movement by means of the eight lock nuts I6.

l5 and normally held Let it be next assumed that the two ante shut-off valves 2i! and the four post shut-oid` valves 22 are opened. Referring to Fig. 1, it is at once evident that as long as an uninterrupted flow of oxygen is caused to pass from the right to the left hand portion of the conduit 2, the jetlike egress of oxygen from the down flow side of the orice 3 will cause a decided pressure drop adjacent thereto. Since the negative pressure escapement holes 4 and S have been purposely located within the aforesaid pressure drop area,

the previously existing no pressure diierential.y

between the top and bottom surfaces of the exible metal diaphragm B is completely upset. A top surface pressure increasepequal toithe above-mentioned pressure drop or decrease, causes each diaphragm 8 to bow down, as viewed in side elevation, such that the four sets of contact points 9 and i5 are no longer in engagement and the signal lamps 24, 26,21 and 2B are thereupon rendered inoperative; a condition utilized to indicate 'satisfactory oxygen now. Since a burned out filament would also render anyone or more ofthe aforesaid lamps inoperative, periodio"check closure of the four post shut-off' valves v22 should be observed as a pre- 'cautionarymeasure.

In Fig. 3, a second set oi signal lamps 24', 26 and 2l" are shown connectedin parallel with a phantom outline of three signal lamps 24, 26 and 2l of Fig. 2, in order that commander D may receive independent warning in the eventl that any one or more 'of his crew members is deprived of his normal i'low of oxygen. Check closure of the first, the second, and the third post shutolf 4valves from the right hand portion of Fig. 2 also vares that the iilaments of the commanders' signal vlamps 2t', 26' and 2' are in pro ier working order.

Fig. i Shows one, though not necessarily a preferred, working embodiment of the pressure sensitive cr-re'acting portion of my invention. This pressure reactor i" is made up of a conduit 2 having a negative pressure escapement hole 4' and Venturi orifice 3' provided in a plug 29 which is further supplied withV a negative pressure escapem'ent hole d in continuation ofsaid :firstmentioned escapement hole Li; of a chamber fixed to the conduitv 2*', having its sealed end connected to the escapement holes i by means ofaconnecting hole 6" and its open end provided with'a threaded-recess i of a gasket 3i), a metal ring 3l, an oxygen resistant diaphragm 3' (of later referred 4to composition) and a second gasliet' 33 seated -for ythe greater part in the `nonthreaded portion of the chamber 5'; and of a diaphragm clamping and conductor portion 32. The clamp-conductor 32 is in turn made up of a disc 33 having a wrench boss 3d with centrally threaded hole 35, two additional threaded holes Eii' and 3l', and two vent holes 33; of a silver tipped metallic contact rod SQ within an insulator iii pressed into a contact screw 4i having a Washer d2 at the base thereof against Which seats a sensitive wire spring i3 terminating at 'its bottom end in a silvered metallic contact point dii; of a metallic locking spring i5 with a mounting base d@ of insulating material secured to the disc 33 by means of a screw il and with a second screw iifor attaching a wire terminal I'l; land or a screw 49 for attaching a wire terniinal it. The diaphragm 8' may be constructed of oxygen-resistant rubber composition, of neoprene, of metal or oi whatever other material is proven best by experimental and service test of my invention by the Army Air Forces and may be further p-rovided with a non-metallic reinforcement patch 5t.

The pressure reactor l of Fig. 4 operates as follows: As initially installed upon the lower end oi the insulator fi, the Sensitive spring d3 holds its contact point it slightly away from the silvered tipped contact rod Eil. To effect a closed contact condition parallel to that previously discussed in connection with the contact points Si and Iii of Fig. l, it is necessary that the contact screw li be screwed down until the reinforcement patch 'dii of the diaphragm 8 is brought into sufficient Contact with the bottom of the-contact point M to bring about such foreshortening of the spring S3 as will cause just thatdegree of engagement between the silvered surfaces or" the contact rod 3&3 and the contact point iii that will insure continuing operation of the signal system connected to the wire terminals Vl and I8'.

Since the -conduit and sealed chambered portions of the pressure reactors l and I are structurallyidentical, it is at once evident that a continuing condition or" oxygen flow through the latterreactor will cause the diaphragm 8' of Fig. 1i to fbow down, as viewed in side elevation, thus permittingthe spring a3 to break contact between ithe silvered surfaces of the contacter rod 39 and the contact point which in turn discontinues-operation of the signal system connectedtothe wire terminals il and i3.

Although-the descriptions of this specification arespeciiic to the illustrations of Figs. l through 4, or readily understood modifications thereof, it is to be understood that there may be departures therefrom which will still clearly fall withiirthe fieldandfscope of the subject invention, andy I therefore do not wish to be restricted thereto,but only in so far as the appended claims are solimited.

Having thus described my invention, what I claim as, new and desire to secure by Letters Patentof Ythe United States is:

1. A flow-responsive electric switch comprising a housing containing a chamber having one side open, a flexible diaphragm ci electrically conductive material covering said open side and being in electrical communication therewith, a diaphragm clamp ring o insulating material for securing said diaphragm pressure tight over said fopenxside, Van adjustable terminal screw centrally .for gfastening. a second terminal wire to said screw, a ow conduit having a single laterally extending passageway communi-eating with said chamber, andmeans restricting the now area ci said conduit near said passageway and upstream .thereof whereby the pressure drop at said laterallyy extending opening operates on Said diaphragmV to separate the two said Contact points `tomaintain an open circuit as long as there is ynormaliiow-in said conduit, but said contacts will -be engaged when flow in said conduit is interrupted.

I2. `A now-responsive electric switch comprising a.. metal housing containing a chamber, a iiow conduit alongside said chamber, a diaphragm .separating said Vchamber into two compartments,

the. one` compartment being connected to the atmosphere, and the iiow conduit being connected by a single lateral passageway to the other compartment, means restricting the ow area of said conduit at said passageway and further restricting said area adjacent said passageway and upstream thereof, an electrical contact member insulatedly supported centrally in said housing on said atmosphere side of said diaphragm, means to adjust said contact member toward or away from said diaphragm, a second contact member 10 between the first contactmember and the diaphragm, spring means urging said second contact member away from the first and toward the wire terminal post means :in electrical communication with said housing.

SIDNEY V. WINTON. 

